基于3自由度并联机器人的船载炮6维运动模拟系统

本系统基于3自由度并联机器人和3维图形仿真实现 了空间6维运动的模拟．构造了一种3自由度并联机构来模拟船的3维转动，并给出了并联平 台的运动学逆解；采用图形仿真虚拟作战环境，模拟船的3维移动，并分析了图形驱动原理 ．     

风洞CTS试验六自由度机构控制方法研究

针对一种风洞CTS试验六自由度运动机构,在分析机构的结构特点和运动关系的基础上,对其控制方法进行研究;六自由度运动机构由3个角位移和3个线位移组成,首先建立机构的运动模型,分析了各轴的传动关系和相互运动关系,针对角度传动的非线性关系特点,采用了基于虚拟轴的跟随控制方法,实现了实际角度的匀速控制;根据六自由度运动关系分析了位置和速度关系,采用速度补偿的方法,实现了六自由度的联动控制;采用高性能的运动控制器和驱动器构成了角度双闭环控制系统,实现了该机构要求的所有运动功能;最后通过实验验证,测量了角度控制精度,结果表明角度控制精度都达到或超过了设计指标,能够满足风洞CTS试验要求。     

并联2-RRR/UPRR 踝关节康复机器人机构及其运动学

在分析现有踝关节康复机器人机构特征的基础上,提出了一种具有远程转动中心的2-RRR/UPRR 并联 踝关节康复机构．该机构可以实现踝关节康复运动所需的三自由度转动,即内翻／外翻,背屈／跖屈,外展／内收运 动．采用关节轴线的运动副螺旋矢量表示法分析了该机构在整个工作空间内任意位姿都可以实现3 维转动的机构学 原理．计算了其自由度,并讨论了选取与定平台相连接的3 个转动副作为输入的合理性．应用球面几何方法给出该 机构的位置反解,同时推导出机构位置正解表达式,并给出了数值算例,验证了其工作空间满足踝关节康复运动的 要求．     

基于SimMechanics的三自由度并联机器人仿真

Delta型机器人是一种三自由度纯平动并联机构,介绍了应用Simulink的SimMechanics模块集对Delta平台进行仿真研究的方法。运用SimMechanics模块对并联机器人进行建模,并根据机构的几何特性建立运动学逆解求取模块,给出动平台规划运动轨迹,通过运动学逆解求取模块生成机构驱动轴输入运动信号,对机构模型进行运动仿真。仿真结果表明,所建立的机械模型和逆解求取模块以及轨迹跟踪都符合实际系统特性,仿真方法高效、实用。     

基于Pro/E和ADAMS的少自由度并联机构运动仿真

本文研究了少自由度并联机构进行运动仿真的方法,应用Pro/E和ADAMS软件结合来进行运动仿真,并在文章中提供了利用这个方法成功对一个三自由度并联机构进行运动仿真的实例.     

五轴并联机床的尺度综合

基于逆向思维提出了一种满足工作空间要求的五轴并联机床的尺度综合方法．首先用极坐标来描述并联机床的姿态空间;然后基于工作空间的要求得到运动平台上铰链点与固定平台上铰链点的距离极值表达式;最后考虑到杆件的力传递性能,得到一组性能较优的参数．该方法对类似的并联机构的尺度综合具有较高的参考价值．     

六自由度运动平台运动学建模与仿真分析

针对并联结构形式的六自由度运动平台,建立了其数学描述方法。通过引入点的复合运动分析理论,建立了平台的完整运动学关系。采用牛顿迭代法进行平台位姿的正解求解,并在此基础上利用解析方法解决了平台速度、加速度正解问题。根据六自由度运动平台的使用特点,提出了一种合理的牛顿迭代初值选择方法。仿真结果表明其迭代寻优次数不超过5次,寻优时间不超过2 ms。分析了计算运动平台包线的理论难度,提出了一种合理的可行方案,经过64次计算,耗时55 ms即完成了平台包线的解算。所建立的运动学模型已应用于某运动平台产品,并可延伸应用于其他并联结构机器人运动分析、并联机床等应用领域。     

关节联动的单孔手术机器人运动解耦方法

针对单孔腔镜手术机器人的执行器械从驱动空间至操作空间的强运动耦合问题,研究关节联动构型,实现运动解耦,简化运动学模型．首先分析联动构型的运动特性并设计滚轮约束式铰接关节．继而研发了7自由度的联动构型器械,它可实现2自由度的“联动展开”．建立了D-H（Denavit-Hartenberg）模型,分析联动构型器械的位姿分离,并通过解析法直接求解逆运动学．然后基于立体角度量手术器械末端在给定点的灵活度,优化联动构型器械的远端段关节布置．实验表明,联动构型器械末端的姿态只取决于远端段关节,“联动展开”只改变器械末端的位置．驱动空间至关节空间的最大误差小于3°,近端段与远端段的驱动之间互不干扰．     

基于边界元法的平面运动并联机构静力学解析

针对混联运动机床开发中所采用的2 自由度平面运动并联机构部分进行了深入的研究．介绍了该平面 运动并联机构的组成,推导了并联机构的运动学正、逆解求解公式,求解了该机构的被动关节．基于边界元法对该 机构的受力情况进行了建模和解析,给出了每个杆件的受力情况．通过ADAMS 仿真验证了求解的正确性,为该机 构的设计开发奠定了基础．本文的分析方法也为并联机构的静力学解析提供了新的思路和方法．     

一种六输入三自由度并联平台机构分析

提出一种六输入、动平台自由度为3的并联平台机构.对于动平台,输入是冗余的.引入协调构件,使机构的自由度为6,所以对于整个机构,输入是确定的,避免了超确定输入协调控制的问题,同时使机构具有冗余驱动机构的优点.将动平台和协调构件的运动作为机构的广义输出,对机构进行了运动学分析,建立了输入和广义输出的映射关系,得到了机构的1阶、2阶影响系数矩阵.应用虚功原理和达朗贝尔原理对机构进行了动力学分析,得到了动力学模型.仿真结果表明,该并联平台机构具有承载能力高等特点,是设计重载并联机构的一种新的解决方案.     

飞行模拟器的结构设计与仿真研究

飞行模拟器具有真实飞行训练无法比拟的优势,其结构设计是优化飞机设计,改善飞行性能的关键问题,故飞行模拟器的建模与仿真研究工作是飞行器设计的难点。通过与液压缸驱动的六自由度飞行模拟器对比分析,以3-RPS机构为基础,以在UG环境下建立的电动缸驱动的三自由度飞行模拟器运动平台模型为研究对象,在ADAMS/View模块下,对其添加约束和驱动后,进行了运动学特性仿真。对于给定的运动学特性曲线,运用ADAMS/Post Processor模块,对测量结果进行后处理,得到各种飞行姿态下的运动学曲线。仿真实验结果验证了该设计可实现升降、横滚、俯仰三种姿态的运动,且符合民航飞行模拟器的技术指标要求。上述分析过程为飞行模拟器的设计提供了一套有效的研究方法。     

Structural synthesis for a lower-mobility parallel kinematic machine with swivel hinges

In this paper, a novel parallel kinematic machine is proposed. Its active platform (main supporting spindle) is manufactured with swivel hinges, that is, we substitute the spherical hinge with a swivel hinge. The active platform is also divided into several layers, which alters the characteristics of a single-layer-platform parallel machine. This paper applies a comprehensive structural approach based on position and orientation characteristics (POC). Each single open chain (SOC) is studied independently from the whole mechanism; we also analyse the POC of each kinematic pair. By the method of union, we obtain the POC matrix of the output motion of each link. Based on the verification of the 5-DOF (degree of freedom) parallel kinematic machine, we construct 3-DOF and 4-DOF parallel mechanisms with swivel hinges through the combination and union of different chains, and develop them into a series.     

Conceptual design and analysis of the 2T1R mechanism for a cooking robot

This paper deals with the design and analysis of a two-translation and one-rotation (2T1R) mechanism for a novel cooking robot. Firstly the motions involved in stir-fry, the most representative operation in the cooking processes used in Chinese cuisine, are analyzed in details. Then the featured motions are decomposed into four main movements that are used as a design base for a wok motion mechanism. Several three-degrees-of-freedom (DOF) parallel manipulators are considered. From these, a 2T1R mechanism is selected as an ideal candidate. A 4-DOF (2T1R+1T) cooking robot is constructed by combining the 2T1R parallel manipulator with a 1-DOF linear feed mechanism. It is shown that the combined 4-DOF robot can perform the required cooking operations, particularly the stir-fry. The analysis conducted on the proposed 2T1R parallel manipulator includes inverse kinematics, forward kinematics, the velocity analysis, the constant orientation workspace, and the total orientation workspace. A prototype of the cooking robot is developed. The experiments verify that the proposed cooking robot is suitable for performing the required operations.     

Optimal design of a 3-PUPU parallel robot with compliant hinges for micromanipulation in a cubic workspace

In recent years, nanotechnology has been developing rapidly due to its potential applications in various fields that new materials and products are produced. In this paper, a novel macro/micro 3-DOF parallel platform is proposed for micro positioning applications. The kinematics model of the dual parallel mechanism system is established by the stiffness model with individual wide-range flexure hinge and the vector-loop equation. The inverse solutions and parasitic rotations of the moving platform are obtained and analyzed, which are based on a parallel mechanism with real parameters. The reachable and usable workspace of the macro motion and micro motion of the mechanism are plotted and analyzed. Finally, based on the analysis of parasitic rotations and usable workspace of micro motion, an optimization for the parallel manipulator is presented. The investigations of this paper will provide suggestions to improve the structure and control algorithm optimization for the dual parallel mechanism in order to achieve the features of both larger workspace and higher motion precision.     

A novel dynamic modelling approach for parallel mechanisms analysis

A novel approach (recursive matrix method), which is used for kinematic and dynamic analysis of a 3-DOF parallel mechanism with revolute actuators, is established in this paper. The active links of the mechanism are actuated by three electric motors and have three independent motions. Knowing the evolution of movable platform, first we develop the positions, velocities and accelerations of all elements of the mechanism. An inverse dynamic problem is solved using the principle of virtual work. Finally, recursive relations and graphs for the torques of three actuators are determined. It showed the efficiency of the proposed method by the example.     

飞行模拟器六自由度运动平台的位置分析与测量控制

针对飞行模拟器六自由度运动平台的位置分析与测量控制进行了研究;依据位置测量元件实时测量到的液压缸长度,运用位置正解算法对运动平台的位置进行了分析,给出了位移传感器的工作原理和位置正解算法模型;利用电液驱动方式组成了体积小、重量轻、加速能力强和快速反应的运动平台控制系统;同时以飞机的俯仰角为例,建立了运动平台驱动信号洗出的算法模型,实现了对模拟座舱的位置和姿态的精确控制;实际应用表明,这些方法是有效可行的,能应用于六自由度运动平台的实际应用中。     

Coupling characteristics of rigid body motion and elastic deformation of a 3-PRR parallel manipulator with flexible links

Modeling of multibody dynamics with flexible links is a challenging task, which not only involves the effect of rigid body motion on elastic deformations, but also includes the influence of elastic deformations on rigid body motion. This paper presents coupling characteristics of rigid body motions and elastic motions of a 3-PRR parallel manipulator with three flexible intermediate links. The intermediate links are modeled as Euler–Bernoulli beams with pinned-pinned boundary conditions based on the assumed mode method (AMM). Using Lagrange multipliers, the fully coupled equations of motions of the flexible parallel manipulator are developed by incorporating the rigid body motions with elastic motions. The mutual dependence of elastic deformations and rigid body motions are investigated from the analysis of the derived equations of motion. Open-loop simulation without joint motion controls and closed-loop simulation with joint motion controls are performed to illustrate the effect of elastic motion on rigid body motions and the coupling effect amongst flexible links. These analyses and results provide valuable insight to the design and control of the parallel manipulator with flexible intermediate links.